Three-stage formation of cap carbonates after Marinoan snowball glaciation consistent with depositional timescales and geochemistry.

ABSTRACT: At least two global "Snowball Earth" glaciations occurred during the Neoproterozoic Era (1000-538.8 million years ago). Post-glacial surface environments during this time are recorded in cap carbonates: layers of limestone or dolostone that directly overlie glacial deposits. Postulated environmental conditions that created the cap carbonates lack consensus largely because single hypotheses fail to explain the cap carbonates' global mass, depositional timescales, and geochemistry of parent waters. Here, we present a global geologic carbon cycle model before, during, and after the second glaciation (i.e. the Marinoan) that explains cap carbonate characteristics. We find a three-stage process for cap carbonate formation: (1) low-temperature seafloor weathering during glaciation generates deep

SUBMITTER: Thomas TB 

PROVIDER: S-EPMC11327254 | biostudies-literature | 2024 Aug

REPOSITORIES: biostudies-literature